CVE-2019-1893 in Enterprise NFV Infrastructure Software
Summary
by MITRE
A vulnerability in Cisco Enterprise NFV Infrastructure Software (NFVIS) could allow an authenticated, local attacker to execute arbitrary commands on the underlying operating system (OS) of an affected device as root. The vulnerability is due to insufficient input validation of a configuration file that is accessible to a local shell user. An attacker could exploit this vulnerability by including malicious input during the execution of this file. A successful exploit could allow the attacker to execute arbitrary commands on the underlying OS as root.
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Analysis
by VulDB Data Team • 10/18/2023
The vulnerability identified as CVE-2019-1893 resides within Cisco Enterprise NFV Infrastructure Software version 3.8.0 and earlier, representing a critical security flaw that undermines the integrity of the underlying operating system. This vulnerability specifically targets the NFVIS platform which serves as the foundation for network function virtualization deployments in enterprise environments. The flaw manifests through inadequate input validation mechanisms applied to a configuration file that is accessible to local shell users, creating an exploitable pathway for authenticated attackers who possess legitimate access to the system. The vulnerability operates at the intersection of privilege escalation and command injection, where the attacker's ability to manipulate system configuration elements directly translates into unauthorized execution of arbitrary code with root privileges.
The technical exploitation of this vulnerability follows a well-defined attack pattern that aligns with common software security weaknesses documented under CWE-20, which addresses "Improper Input Validation." The attacker must first establish a legitimate local shell session on the affected device, then manipulate a specific configuration file that undergoes insufficient validation during processing. When the system processes this malformed configuration file, the inadequate input sanitization allows malicious payloads to be executed within the context of the underlying operating system. This type of vulnerability represents a classic privilege escalation vector where local access is leveraged to achieve root-level command execution, effectively compromising the entire system's security posture.
The operational impact of CVE-2019-1893 extends far beyond simple command execution capabilities, as it provides attackers with complete control over the affected NFVIS device and its underlying infrastructure. This vulnerability enables adversaries to perform actions such as modifying system configurations, installing persistent backdoors, exfiltrating sensitive data, and potentially using the compromised device as a launch point for lateral movement within the network. The implications are particularly severe in enterprise NFV environments where these devices often serve as critical network infrastructure components managing virtualized network functions including firewalls, load balancers, and other security services. The vulnerability's presence in the configuration file processing pipeline means that any configuration changes or updates could be exploited, creating ongoing security risks throughout the device's operational lifecycle.
Mitigation strategies for CVE-2019-1893 should prioritize immediate patching of affected Cisco NFVIS software versions to the latest available releases that contain the necessary input validation fixes. Organizations should implement strict access controls and principle of least privilege configurations to minimize the number of local users with shell access, while also conducting regular security audits of configuration files and system processes. Network segmentation and monitoring solutions should be deployed to detect anomalous command execution patterns that might indicate exploitation attempts. The vulnerability's characteristics align with ATT&CK technique T1059.001 for Command and Scripting Interpreter, and T1068 for Exploitation for Privilege Escalation, making it a target for both automated scanning tools and sophisticated adversaries seeking to establish persistent access to enterprise network infrastructure. Security teams should also consider implementing file integrity monitoring solutions to detect unauthorized modifications to critical configuration files that could be leveraged for exploitation.